feat(ui): Convert interval seconds to days, hours, minutes, and seconds (#5220)

Co-authored-by: Frank Elsinga <frank@elsinga.de>

server/server.js

@@ -720,6 +720,17 @@ let needSetup = false;
 
                 monitor.rabbitmqNodes = JSON.stringify(monitor.rabbitmqNodes);
 
+                /*
+                 * List of frontend-only properties that should not be saved to the database.
+                 * Should clean up before saving to the database.
+                 */
+                const frontendOnlyProperties = [ "humanReadableInterval" ];
+                for (const prop of frontendOnlyProperties) {
+                    if (prop in monitor) {
+                        delete monitor[prop];
+                    }
+                }
+
                 bean.import(monitor);
                 bean.user_id = socket.userID;